Brain Pathology Case of the Month - March 2000

FINAL DIAGNOSIS: LYMPHOPLASMACYTE-RICH MENINGIOMA

DISCUSSION:

This 43-year-old patient presented with partial seizures, which had generalized after 6 months by. The radiological appearance of the parietal, parasaggital, extra-axial tumor including the vascular supply from the external carotid artery system as seen on angiography, was indistinguishable from that associated with meningioma. The histological appearance of the surgically removed tumor was unusual. An extensive lymphoplasmacytic infiltration obscured the meningothelial component of the tumor, which required immunohistochemistry to rule out a lymphoproliferative process. Following the terminology of the WHO (6) we classified the tumor as a lymphoplasmacytic-rich meningioma, a rare meningioma variant (1, 5, 8,10). Given the follicular architecture of the lymphoid infiltrate we also considered the diagnosis of Castelman's disease, an uncommun lymphoproliferative disease (3) known also as angiofollicular lymphoid hyperplasia, which generally arises in the mediastinum but, of which a meningeal localization has been described (2,9). There is some evidence that this lesion can be associated with systemic inflammatory and/or autoimmune states (2). The immunohistochemical analysis enabled us to identify the meningothelial component of the tumor thus to exclude the diagnosis of Casteman's disease. In the differential diagnosis of lymphoplasmacyte-rich meningioma, one have to exclude other meningeal-based haematological conditions. This type of meningioma is frequently associated with systemic lymphoproliferative diseases, and with an immuncompromised state (2, 6, 7). An association between lymphoplasmacyte-rich meningioma and a systemic hypergammaglobulinemia was observed by several authors (4, 5). A correlation between the rise and fall of hypergammaglobulinemia and the removal and regrowth of the lymphoplasmacyte-rich meningioma in the case of a 14-year-old boy was documented by Gi et al., (4). The biological behavior of these meningiomas seems to depend on the meningioma component but, as the lesion may be associated with haematological abnormalities, a close postoperative follow-up of patients with this type of meningioma is needed.

REFERENCES

Bannerje AK, Blackwood W (1971) A subfrontal tumour with the features of plasmocytoma and meningioma. Acta Neuropathol 18: 84-88